Logging SQL queries in android

Question

I am using the query functions in order to build the SQL queries for my tables. Is there a way to see the actual query that is run? For instance log it somewher

Answer 1

If you are using SQLiteDatabase with it's standard methods as insert, update and delete custom CursorFactory will not be working.

I implemented my not very great but working solution based on SQLiteDatabase class. It just repeats logic of insert, update and delete methods but without statements and actually doing the logging of SQL statements.

public class SQLiteStatementsLogger {

    private static final String TAG = SQLiteStatementsLogger.class.getSimpleName();

    private static final String[] CONFLICT_VALUES = new String[]
            {"", " OR ROLLBACK ", " OR ABORT ", " OR FAIL ", " OR IGNORE ", " OR REPLACE "};

    public void logInsert(String table, String nullColumnHack, ContentValues values) {
        logInsertWithOnConflict(table, nullColumnHack, values, 0);
    }

    public static void logInsertWithOnConflict(String table, String nullColumnHack,
                                     ContentValues initialValues, int conflictAlgorithm) {
        StringBuilder sql = new StringBuilder();
        sql.append("INSERT");
        sql.append(CONFLICT_VALUES[conflictAlgorithm]);
        sql.append(" INTO ");
        sql.append(table);
        sql.append('(');

        Object[] bindArgs = null;
        int size = (initialValues != null && initialValues.size() > 0)
                ? initialValues.size() : 0;
        if (size > 0) {
            bindArgs = new Object[size];
            int i = 0;
            for (String colName : initialValues.keySet()) {
                sql.append((i > 0) ? "," : "");
                sql.append(colName);
                bindArgs[i++] = initialValues.get(colName);
            }
            sql.append(')');
            sql.append(" VALUES (");
            for (i = 0; i < size; i++) {
                sql.append((i > 0) ? ",?" : "?");
            }
        } else {
            sql.append(nullColumnHack + ") VALUES (NULL");
        }
        sql.append(')');
        sql.append(". (");
        for (Object arg : bindArgs) {
            sql.append(String.valueOf(arg)).append(",");
        }
        sql.deleteCharAt(sql.length()-1).append(')');
        Log.d(TAG, sql.toString());
    }

    public static void logUpdate(String table, ContentValues values, String whereClause, String[] whereArgs) {
        logUpdateWithOnConflict(table, values, whereClause, whereArgs, 0);
    }

    public static void logUpdateWithOnConflict(String table, ContentValues values,
                                        String whereClause, String[] whereArgs, int conflictAlgorithm) {

        StringBuilder sql = new StringBuilder(120);
        sql.append("UPDATE ");
        sql.append(CONFLICT_VALUES[conflictAlgorithm]);
        sql.append(table);
        sql.append(" SET ");

        // move all bind args to one array
        int setValuesSize = values.size();
        int bindArgsSize = (whereArgs == null) ? setValuesSize : (setValuesSize + whereArgs.length);
        Object[] bindArgs = new Object[bindArgsSize];
        int i = 0;
        for (String colName : values.keySet()) {
            sql.append((i > 0) ? "," : "");
            sql.append(colName);
            bindArgs[i++] = values.get(colName);
            sql.append("=?");
        }
        if (whereArgs != null) {
            for (i = setValuesSize; i < bindArgsSize; i++) {
                bindArgs[i] = whereArgs[i - setValuesSize];
            }
        }
        if (!TextUtils.isEmpty(whereClause)) {
            sql.append(" WHERE ");
            sql.append(whereClause);
        }
        sql.append(". (");
        for (Object arg : bindArgs) {
            sql.append(String.valueOf(arg)).append(",");
        }
        sql.deleteCharAt(sql.length()-1).append(')');
        Log.d(TAG, sql.toString());
    }

    public static void logDelete(String table, String whereClause, String[] whereArgs) {
        StringBuilder sql = new StringBuilder("DELETE FROM " + table);
        if (!TextUtils.isEmpty(whereClause)) {
            sql.append(" WHERE " + whereClause);
            sql.append(". (");
            for (Object arg : whereArgs) {
                sql.append(String.valueOf(arg)).append(",");
            }
            sql.deleteCharAt(sql.length()-1).append(')');
        }
        Log.d(TAG, sql.toString());
    }
}

Be aware not to use the logger in release versions. It might increase time of queries executing. You can check if the build is in debug mode with this code line:

0 != (getApplicationInfo().flags & ApplicationInfo.FLAG_DEBUGGABLE)

Answer 2

If you are using a ContentProvider to access the DB, this is how I got it logging the queries. Not a perfect solution, but it works for development

@Override
  public boolean onCreate() {
    dbHelper = new MySQLiteHelper(getContext());
    database=dbHelper.getWritableDatabase();

    if(!database.isReadOnly())
      database.execSQL("PRAGMA foreign_keys=ON;");
    return true;
  }            

  SQLiteDatabase.CursorFactory cursorFactory = new SQLiteDatabase.CursorFactory() {      
    @Override
    public Cursor newCursor(SQLiteDatabase db, SQLiteCursorDriver masterQuery, String editTable, SQLiteQuery query) {
      Log.d(TAG, "Query: "+query);

      return new SQLiteCursor(db, masterQuery, editTable, query);
    }
  };

  @Override
  public Cursor query(Uri uri, String[] projection, String selection,
      String[] selectionArgs, String sortOrder) {
    String table =getTableName(uri);

    if(Constants.LOG_QUERIES){
      database = SQLiteDatabase.openOrCreateDatabase(database.getPath(), cursorFactory);
    }

    Cursor cursor =database.query(table,  projection, selection, selectionArgs, null, null, sortOrder);
    cursor.moveToFirst();

    return cursor;
  }

It'll throw a DatabaseNotClosed exception, but you'll be able to see the query

Answer 3

Personnally I log text using java.util.Log and the Log.w("MYAPPNAME", "My text...") function. It shows up in the Log view of Eclipse and it can be filtered to output only the logs for "MYAPPNAME".